cast-in-place arch-slab roof truss
precast large roof slab
roof truss of arch slab
Changing flat roof to slope roof
diagonal ridge for hip roof，vertical ridge for gable roof
flat- roof-to- slope-roof
flat-roof-to-slope-roof
flat-roof-to-sloping roof
roof pressure roof weight
roof prism (=roof-angle prism)
10104 m3 floating roof tank